Archive for the ‘Green Patents’ category

I Want My MTPV: Recovering Waste Heat By Micron-Gap Thermal Photovoltaics

April 11th, 2010


I read an interesting article in The Economist’s most recent Technology Quarterly about new ways to recycle waste heat from power plants and other types of machinery such as computers. 

In the power generation context this typically is done using a heat recovery unit to capture heat from a combustion unit’s exhaust stream.

Another way to way to recycle waste heat is to capture infrared radiation emitted by hot objects using photovoltaic cells. 

The difficulty with this approach is that only photons that travel at a near perfect right angle to the surface of the hot material can escape and be picked up by PV cells.  Photons traveling at any other angle are reflected back inside the material.

One of the companies profiled in the Economist article is Boston, Massachusetts startup MTPV Corporation (MTPV), which takes its name from an acronym for a technology called micron-gap thermal photovoltaics. 

MTPV discovered that by placing PV cells just a few hundred nanometers from a hot surface of silicon carbide alloy – so the gap is smaller than the wavelength of the infrared radiation – the photons are not reflected inward but instead continue to travel into the PV cells.

According to MTPV’s web site, U.S. Patent No. 6,084,173 (‘173 Patent), entitled “Method and apparatus for the generation of charged carriers in semiconductor devices,” is its “fundamental” patent on the micron-gap technology. 

The ‘173 Patent is directed to methods of enhancing electrical current generation in a conductive surface by adjusting the gap between a hot surface and the conductive surface to the order of microns or submicrons.

The MTPV web site describes U.S. Patent No. 6,232,546 (‘546 Patent) as a version 1 “implementation” patent.  The ‘546 Patent is entitled “Microcavity apparatus and systems for maintaining a microcavity over a macroscale area” and is directed to a microscale generator (10) having two elements (14, 16) within a vacuum (12).  

The first element (14) acts as a thermal source for transferring energy and a second facing element (16) receives the energy transferred.


Moveable panels (18) are disposed on one of the elements.  The panels (18) are thermally coupled to element (14) and spaced from facing element (16) a predetermined, sub-micron distance to efficiently couple the energy between the elements so it can be converted to electricity.

To maintain and control the requisite sub-micron distance between the elements, each individual panel includes spring-like actuating flexures (20).  These flexures (20) urge each panel (18) towards facing element (16) to maintain the predetermined sub-micron spacing between the elements.


Each panel (18) has its own flexures (20) so the panels act independently of each other to conform to and compensate for surface variations in element (16).

In addition to the ‘173 and ‘546 Patents, MTPV owns U.S. Patent Applications Pub. Nos. 2008/0060694, 2009/0188549 and 2009/0277488.  According to the company’s web site MTPV continues to innovate and grow its patent portfolio:

The intellectual property continues to extend with six pending patent applications and over fifty disclosures in addition to ongoing research and development efforts.

Samsung, Toshiba et al. Accused of Infringing Energy Conservation Circuit Patent

April 1st, 2010

A company called Commonwealth Research Group LLC (Commonwealth) filed a patent infringement suit last month against a number of technology companies, accusing them of infringing a patent relating to an energy saving system for electronic devices.

The complaint (commonwealth_complaint.pdf), filed in federal court in Delaware, asserts U.S. Patent No. 6,026,493 (‘493 Patent) against Samsung, Toshiba, NXP Semiconductors and Renesas Technology.

The ‘493 Patent is directed to electronic circuitry that conserves energy by turning off or reducing power to selected chip components.  A disclosed embodiment involving powering a tape recorder is shown below.  The embodiment comprises a circuit having two relays (12, 18).


In its normal position, the second relay (18) supplies continuous power to the power bus.  The first relay (12) is designed to lock open as long as power is maintained on the power bus.   

Tape sensor prongs (27) momentarily connect on a passing cassette tape (26) to energize the second relay (18).  When the second relay (18) is energized, the power bus loses power, and the first relay (12) returns to the normal position with no power supplied to the tape recorder (14).

It is unclear from the complaint who or what Commonwealth is.  The complaint does not say anything about the company except that it is a Virginia corporation that owns all rights to the ‘493 Patent. 

The only other information I could find on the internet was through a search of the U.S. Patent and Trademark Office assignments database, which lists a Washington, DC address for Commonwealth. 

Commonwealth has requested a preliminary and permanent injunction, which would require the company to explain how it’s been harmed by the alleged infringement.  More details are likely to come out at that time.

Wartsila and Topsoe Make Methane Into Energy With First Landfill Gas Fuel Cell Unit

March 28th, 2010


An interesting article from Distributed Energy magazine discusses a methane gas-fed fuel cell power unit developed by diesel and gas engine maker Wartsila.  According to the article, the Finnish company’s WFC20 is the first solid oxide fuel cell unit run on methane rich landfill gas.

Wartsila has finished the first phase of its validation program for the fuel cell unit, which has been in successful operation for more than 1500 hours. 

Wartsila owns several international patent applications relating to power plant technology, including combined cycle operating methods that recycle waste heat and a method of operating a combined fuel cell – piston engine plant.

The WFC20 is based on planar solid oxide fuel cell (SOFC) technology supplied by Danish fuel cell maker Topsoe Fuel Cell A/S (Topsoe).  According to Topsoe’s web site, SOFC fuel cells are the most efficient fuel cells available, recuperating the heat from its high operational temperature. 

Topsoe owns several international patent applications directed to its SOFC technology and fuel cell stacks, including Application No. PCT/EP2008/000527 (‘527 Application).

The ‘527 Application is directed to an SOFC stack and clamping structure that uses a flexible sheet instead of conventional planar end plate flanges.  This reduces the amount of material needed for the fuel cell stack.  

The SOFC stack is inserted between two insulating blocks (12) (second insulating block on opposite side not shown).  The flexible sheet 15 is forced into a convex shape when in contact with the insulating end block 12.


According to the ‘527 Application, the flexible sheet 15 does not have to withstand bending forces so the mechanical tension lies in the plane of the flexible sheet, thus avoiding deformation of the fuel cell components.   The compressive force is obtained after clamping using nuts 8, springs 7 and tie rods 6. 

It’s Not Easy Being Green: Navigating the USPTO’s Green Tech Pilot Program

March 20th, 2010

It’s been three months since the U.S. Patent and Trademark Office (PTO) launched the Green Technology Pilot Program, which allows patent applicants to petition for expedited examination for certain green tech inventions.

Some initial reports indicate that the response to the program has been “underwhelming” so far, with well short of the 3,000 available slots being filled (see post here).

Moreover, the vast majority of petitions actually filed are being denied.  As I discovered first-hand, the most common ground for denial of a green tech petition is that the patent application is not in an eligible technology class and subclass.

This is at least in part because the universe of eligible classes and subclasses represents only a subset of technology that is actually green.

The question of technology class is not one patent practitioners typically consider in the ordinary course of patent prosecution.  However, it is crucial to acceptance into the Green Technology Pilot Program and can make navigating the program quite tricky.  

I recently filed a petition for the program and had the petition rejected for being in an ineligible class.  After some research, telephone calls with PTO employees and claim amendments, my petition for reconsideration was granted and the application accepted into the program.

Based on my experience, here is a suggested framework for getting a patent application that has not yet been assigned a class/subclass, or has been assigned an ineligible class/subclass, classified or reclassified, respectively, in an eligible technology class.

First, peruse the list of technology classes and subclasses eligible for the program and select a few that seem good candidates for the patent application (see the list of eligible classes/subclasses in the notice of program here).  

Then research those classes/subclasses on the PTO web site.  The full list of technology classes and subclasses can be searched via the patent classification home page.

Each class covers a broad technology category, and each subclass a particular aspect of that technology.  Significantly, each subclass has a definition that includes key words or concepts that trigger assignment of a patent application into that subclass.

Study the key words and concepts to determine whether they match any elements of your patent claims or whether the claims could be amended to match the subclass. 

The key, I discovered, is to amend the most comprehensive claims of the application, meaning the dependent claims that incorporate the most invention features, or limitations, because it is these claims the PTO looks at to determine the appropriate classification.

At this point, I believe an important step is to get some direction from inside the PTO, specifically from the supervisory patent examiner (SPE) in charge of the particular technology class you’re targeting. 

To do this, figure out the PTO art unit that handles the target technology class or classes.  That info is available at this PTO web page.

I found that the SPEs are quite helpful and will provide some direction as to what types of features need to be in the claims to get the application into a particular technology class and subclass.  They can’t guarantee success, of course, but they can provide some reassurance that you’re heading in the right direction with your claim amendments.

Then prepare a preliminary amendment that amends a number of dependent claims to incorporate the key words and concepts of one or more of the target subclasses in accordance with the feedback of the SPE. 

The preliminary amendment accompanies the petition, which should contain a list of the target classes/subclasses and a statement that the applicant believes the application is appropriately classified in one or more of those subclasses because of the particular features in the amended claims.

If your initial petition for the program has been rejected and you’ve drafted claim amendments in the context of asking for reconsideration of the rejection decision, there is one important final step.

That is to have a telephone call with the PTO employee who will receive your petition for reconsideration.  The notice of rejection should list a name and phone number for an individual you can call with questions about the decision.

I had several conversations with the individual listed in our initial notice of rejection.  He was very helpful and suggested that I call a day or two after I filed the petition for reconsideration and preliminary amendment to give him a head’s up that the petition was on its way.

I suggest doing the same so the individual is aware of your efforts and that the petition has been filed.  He may also confirm that he will forward your petition to the SPE in charge of the class/subclass you’re trying to get into.  This extra step could help push your application over the finish line.

Why go through all this effort?  An application accepted into the Green Technology Pilot Program jumps to the front of the line and begins examination immediately instead of languishing for what can be 2-3 years to be examined in the ordinary course.

Court Grants Zep Solar’s Motion to Dismiss Rival’s Non-Infringement DJ

March 15th, 2010


In a previous post, I discussed a patent infringement suit filed by solar installer Akeena Solar against Zep Solar, Inc. (Zep), groSolar and High Sun Technology, Inc. (HST) in the Northern District of California. 

Akeena’s complaint (akeena_complaint.pdf) accused groSolar and HST of infringing U.S. Patent No. 7,406,800 (‘800 Patent”), entitled “Mounting system for a solar panel” and directed to an integrated module frame and racking system for solar panels.   According to the complaint, Zep’s solar panel mounting system infringes the ‘800 Patent, and groSolar has teamed up with Zep to distribute and install Zep systems.

The complaint also included a claim against Zep and HST for a declaratory judgment (DJ) that Akeena does not infringe Zep’s U.S. Patent No. 7,592,537 (‘537 Patent), entitled “Method and apparatus for mounting photovoltaic modules.” 


The ‘537 Patent is directed to a photovoltaic module mounting system (10) comprising two adjacent interlocking PV module frames (12L, 12R).  Each frame encloses the perimeter of a PV laminate (14) in recesses (23L, 23R).  The interlocking mechanism may comprise a separate male coupling member (28) inserted into female channel portions (26L, 26R).

Last month the court dismissed Akeena’s non-infringement DJ claim, finding there was no actual controversy between the parties about the ‘537 Patent (zep_order.pdf).

Akeena had alleged there was an actual controversy sufficient for DJ jurisdiction because of certain e-mails and telephone conversations between the parties including a Zep e-mail to Akeena’s counsel to bring the ‘537 Patent to Akeena’s attention, an e-mail from Zep’s CEO to Akeena’s president stating that “Zep’s legal team is ready for a fight if that is what is needed,” and a telephone conversation in which Zep’s CEO allegedly told Akeena’s president that he would “blow up” Akeena’s patent.

But the court found that the communications at issue were made in response to Akeena’s infringement threats and merely signaled Zep’s intention to preserve its legal rights:

Significantly, Zep’s communications to Plaintiffs have all been in response to Plaintiffs’ accusations of infringement and direct threats of an infringement lawsuit.  Objectively, all of Zep’s statements are reasonably read merely as preserving Zep’s legal rights, including the right to attack the validity of Plaintiffs’ patent and to assert Zep’s patent if sued by Plaintiffs.

The court also found it significant that, since the lawsuit was filed, Zep hasn’t asserted a counterclaim that Akeena infringes the ‘537 Patent.

Temple Law School Symposium to Address Green IP

March 11th, 2010


The Temple Journal of Science, Technology, and Environmental Law’s (TJSTEL) 2010 annual symposium will be about legal issues at the intersection of intellectual property and green technologies.

Entitled “The Greening of Intellectual Property,” the symposium will examine

the many points of intersection between the intellectual property field and the green movement and assess the importance of this overlap to the legal community, the nation, and the world

The speakers include Robert Bahr, the Acting Associate Commissioner for Patent Examination Policy, who will talk about the USPTO’s Green Technology Pilot Program and Duke Law Professor Jerome Reichman, who will speak about green innovation strategies.

The first panel is entitled “IP Rights:  Helping or Hurting Green Technology? The Effect of Green Energy Patents on Pollution and Emissions Programs in Developing Countries” and will be moderated by Temple Professor Greg Mandel.

The second panel will discuss the effects of recent court decisions such as In re Bilski on green patenting.  An ethics panel will include Daniel Desmond, Pennsylvania’s “Energy Czar,” who has been involved in developing the state’s alternative energy policies.

The symposium will be held on Friday, March 19th at Temple University.  The full schedule is here: schedule-of-events-2010.pdf.  Registration information is available here.

Green IP has become a hot academic topic, with several law schools holding symposia on the subject in the last year or so. 

Greenshift Seeks Quick Injunction Against Cardinal Ethanol

March 8th, 2010


In a previous post, I wrote about GreenShift Corporation’s (GreenShift) patent suit against GEA Westfalia Separator, Inc. (Westfalia), in which GreenShift accused the New Jersey-based separator and decanter maker of infringing U.S. Patent No. 7,601,858 (‘858 Patent).

Last month GreenShift asserted the ‘858 Patent again, alleging that Indiana ethanol maker Cardinal Ethanol (“Cardinal”) is infringing the patent by using equipment that employs the patented ethanol processing methods.  The suit was filed in federal court in Indianapolis.

The ‘858 Patent is entitled “Method of processing ethanol byproducts and related subsystems” and is directed to methods of recovering oil from byproducts of ethanol production. 

Ethanol production by dry milling creates a waste stream comprised of byproducts called whole stillage.  According to the ‘858 Patent, whole stillage contains valuable oil but prior processes for recovering this oil have been expensive or inefficient.

GreenShift’s patented methods include mechanically separating the whole stillage into distillers wet grains and thin stillage and then running the thin stillage into an evaporator to form a concentrated byproduct, or syrup.  The syrup is fed through a second centrifuge, which separates usable corn oil from the syrup.

Along with the complaint, GreenShift filed a motion for preliminary injunction (PI), in which it argued that it has a strong likelihood of proving infringement, the ‘858 Patent is valid, and it would suffer irreparable harm if Cardinal is not enjoined (see packet including GreenShift’s press release, the complaint and the PI motion here).

The PI motion includes a detailed claim chart that seeks to demonstrate Cardinal’s alleged infringement of claims 8, 10, 12, 13, 14 and 16 of the ‘858 Patent. 

As to the alleged harm, GreenShift states that Cardinal’s infringement is causing it to suffer “loss of market share, opportunities, revenue and goodwill” as well as damage to its “reputation as a technology pioneer.”

In A Third Action Against Mitsubishi, GE Asserts New Zero Voltage Ride Through Patent

March 4th, 2010


In previous posts here and here, I discussed the General Electric Company’s (GE) two wind turbine patent actions against Mitsubishi, one in the U.S. International Trade Commission (ITC) and the other in federal court in the Southern District of Texas. 

Last month GE added a third case to the mix when it sued Mitsubishi for infringement of two patents relating to a wind turbine base frame and zero voltage ride through (ZVRT) technology. 

Filed in the Northern District of Texas in Dallas, the complaint (gecomplaint.pdf) identifies Mitsubishi’s 2.4 megawatt wind turbine as the allegedly infringing product.

The patents-in-suit are U.S. Patent Nos. 6,879,055 (‘055 Patent) and 7,629,705 (‘705 Patent).  The ‘055 Patent is directed to a two-part base frame for arranging a drive train on the tower of a wind turbine.

The upper part (6) of the base frame carries the drive train, and the lower part (16) of the base frame has an azimuthal drive device (23), which rotates azimuthally to adjust the rotor axis as a function of wind direction. 


The connection point (15) that joins the upper and lower parts of the base frame extends along a horizontal cross-section having a larger dimension in the direction of the rotor axis than in the perpendicular direction. 

According to the ‘055 Patent, this construction of the connection point (15) is favorable for absorption of stress from the rotor.  The two-part design also makes transport and assembly of the base frame easier.

The ‘705 Patent, which issued in December 2009, relates to methods of facilitating zero voltage ride through so the turbine can remain online during voltage dips down to zero volts. 

As the ‘705 Patent explains, some gearless direct drive wind turbine generators include power converters, and both the generators and the converters are susceptible to grid voltage fluctuations. 

The patented methods mitigate wind turbine generator trips during events in which voltage amplitude decreases to zero volts, as opposed to known low voltage ride through methods that can handle less extreme voltage drops.

The patented systems and methods include a phase-locked loop (PLL) regulator to receive voltage measurement signals from a plurality of voltage transducers.  The PLL regulator includes a PLL that receives the sinusoidal voltage measurement signals.

If a voltage amplitude is outside a pre-determined range, an algorithm within the PLL generates a control signal and the PLL regulator changes to a different mode or state of operation.  A plurality of states of operation are possible, with varying parameters such as gain constants.

According to the ‘705 Patent:

the plurality of states of operation facilitate zero voltage ride through (ZVRT) as well as other grid faults while also facilitating normal operation   

This lawsuit comes shortly after the ITC terminated GE’s complaint against Mitsubishi.  GE’s infringement suit in the Southern District of Texas has been stayed pending a final determination of the ITC case.

CO2 Effects Not So Nice? Use it Twice, Says Carbon Sciences

February 8th, 2010


Carbon Sciences is a Santa Barbara, California company that has developed a proprietary process to recycle carbon dioxide emissions into gasoline and other liquid fuels.

The company breaks down CO2 and extracts the carbon atoms to make new hydrocarbon chains.  According to its web site, Carbon Sciences’ process requires less energy and is more scalable than previous known techniques, which used expensive inorganic catalysts.

The key to the process is a multi-step biocatalysis that uses organic biocatalysts.  The company’s biocatalytic method uses inexpensive, renewable biomolecules to catalyze certain chemical reactions required to transform CO2 and water into fuel molecules.

Through nano-engineering of the biocatalysts and efficient process design, Carbon Sciences can operate these catalysis steps on a large industrial scale.  In particular, the company’s smart particle technology provides improved encapsulation of the enzymes that prolongs their effective lives and allows them to perform many reaction cycles.

The major components of the process are a CO2 Flue Gas Processor, a a Biocatalyst Unit, a Biocatalytic Reactor Matrix, a Filtration system and a conversion and polishing unit.


The Biocatalytic Reactor Matrix is the heart of the process.  It is here, in a matrix of liquid reaction chambers, that the large quantities of biocatalysts perform the multi-stage breakdown of CO2 and transformation to hydrocarbons.

The company’s CEO, Byron Elton, told me that Carbon Sciences has filed four as yet unpublished patent applications directed to its CO2 recycling process.  Elton expects the company to file 4-6 more new patent applications this year. 

Carbon Sciences owns U.S. Patent Application Publication No. 2008/0277319 (‘319 Application), entitled “Fine particle carbon dioxide transformation and sequestration.”  According to Elton, the ‘319 Application covers the company’s initial forays into carbon capture and sequestration.

The ‘319 Application is directed to methods and systems for breaking down carbon dioxide into micron- or sub-micron-sized particles, classifying or separating out the particles of a desired size and reacting those particles to form mineral carbonates.

Carbon Sciences’ technology extends into several aspects of CO2 capture, sequestration and recycling, including advanced chemical processes that can use flue gas and brackish water to capture CO2 emissions and scrub it to yield pure CO2.

Because the market for gasoline and liquid fuels is likely to remain quite large for some time, Carbon Sciences’ recycling process provides an interim carbon mitigation option:  use the CO2 molecule twice.

eSolar and Penglai Electric Co. Enter Master Licensing Agreement for Solar Thermal Power in China

February 5th, 2010


eSolar is a Pasadena, California solar thermal startup that makes solar power plants using flat mirrors, or heliostats, to concentrate sunlight onto a centrally located water tank suspended on a tower.  This type of structure is known as “power tower” architecture.

Founded in 2007, eSolar has seen very rapid success in business deals to implement and deploy its technology.  The latest, which is the biggest solar thermal deal ever, is a master licensing agreement with Chinese electrical power equipment manufacturer Penglai Electric (Penglai).

Penglai will develop at least 2 gigawatts of solar thermal power plants in China over the next 10 years using eSolar’s technology.

eSolar owns at least four published U.S. patent applications and at least half a dozen international applications relating to its solar thermal technology.  U.S. Patent Applications Pub. Nos. 2009/0241938 and 2009/0241939 are directed to solar receivers and U.S. Patent Application Pub. No. 2009/0107485 is directed to calibration and tracking control systems for heliostats. 

According to the technology description on eSolar’s web site, its cost-effective utility scale power plant is “based on mass-manufactured components and designed for rapid construction, uniform modularity, and unlimited scalability.”  The company’s heliostat is the “building block” of its power plants and is designed for deployment in pre-fabricated “heliostat sticks” for easy installation.

One factor that affects the efficiency of power tower plants is the positioning of the heliostats relative to the tower and to each other.  eSolar’s “modular field” of concentrating mirrors consists of thousands of systematically spaced heliostats arranged to optimize the layout and maximize efficiency. 

U.S. Patent Application Pub. No. 2009/0133685 (‘685 Application) is directed to eSolar’s heliostat array layouts.  Some embodiments of the ‘685 Application comprise three segments (128) with each segment divided into two variably spaced heliostat zones (128a, 128b).


Heliostats (328a) in the first zone (128a) are spaced closer together than heliostats (328b) in the second zone (128b).  The heliostat locations are also staggered with respect to heliostat locations in adjacent rows.  A thermal receiver (228) is mounted on a central power tower.

Last year, eSolar entered into a similar deal with an Indian partner, ACME Group (ACME), to build solar thermal plants generating up to 1 gigawatt of power in India.  ACME is the exclusive licensee of eSolar’s technology in India.

eSolar’s success in deploying its solar thermal technology in emerging markets such as India and China belies claims by those countries and other developing nations that IP rights are acting as a barrier to transfer of clean technologies (see China View article here and my previous post here). 

Various proposals to weaken or eliminate IP rights, including compulsory licensing and even excluding green technologies from patent protection, have been put forth by India, China and other emerging market and developing countries and were contained in the official UNFCCC negotiating text for the Copenhagen meetings in December.

However, eSolar’s success in finding willing partners in India and China may actually be driven, at least in part, by intellectual property protection:  it’s hard to imagine Penglai or ACME investing in such large scale projects without the exclusivity in their home markets guaranteed by the master license agreements.

eSolar’s China deal was announced in early January.  It’s interesting that while climate change treaty negotiators were discussing IP as a barrier to international clean tech transfer eSolar and Penglai were probably finalizing the terms of the master license agreement that would be part of the largest ever transfer and deployment of solar thermal technology to China.